Date on Master's Thesis/Doctoral Dissertation


Document Type

Doctoral Dissertation

Degree Name

Ph. D.



Committee Chair

Ewald, Paul William

Author's Keywords

Depression; Women's health; Estrogen; Trytophan; Chlamydia


Depression in women; Drugs--Side effects


Depression is one of the most frequent causes of disability worldwide. It can affect the psychological, social, and physical wellbeing of those that suffer from it, the majority of which are women. Depression has been linked to immune activation as well as serotonin depletion through a reduction in its precursor, tryptophan. Chlamydia trachomatis infection and estrogen can influence both the immune system and tryptophan levels, thereby biochemically inducing a depressive state. If this is the case, the use of exogenous estrogen through oral contraceptive pills (OCPs) could increase depressive symptoms, while the use of antibiotics to treat C. trachomatis infection could decrease depression. This thesis examined whether depression status in subjects was correlated with infection and medication use. Women were screened for depression at their annual gynecological exam, during which time they would receive an STI screen as standard of care. The study was conducted at the University of Louisville GYN/OB Foundation clinic and Campus Health Services from 2009-2011. Subjects were given a Beck Depression Inventory (BDI) to assess depressive symptoms and asked to keep a calendar of medication use. Subjects returned after one month to take a second BDI and their scores and medication calendars were compared with their medical records, specifically infection status and existing medical conditions. BDI scores decreased significantly in the follow-up assessment relative to the initial assessment. This decrease was correlated with the extent to which the subjects used mood-altering medications. Birth control use was correlated with an increase in depressive symptoms, but subjects who took mood-altering medication in addition to birth control were not more depressed than those that did not take birth control. There were insufficient data to correlate sexually transmitted infections, particularly C. trachomatis, with depressive symptoms. These findings show that increased hormonal birth control use is correlated with an increase in depression, but this depression is ameliorated with the use of mood-altering medication. These results imply that antidepressive medication may be particularly effective in treating depression associated with estrogen or oral contraceptive pills.